Monthly Archives: May 2017

Heliconia: plants with personality

Orange-hatted Dusty Gannon’ (my hummingbird name) visiting Heliconia tortuosa

In the Department of Botany and Plant Pathology, first year graduate student Dusty Gannon is studying how Heliconia tortuosa, a tropical plant with long, tubular flowers and vividly-colored bracts (modified leaves that house the flowers), maintains its unique relationship with pollinating hummingbirds. Although hummingbirds universally love nectar, they have diverged into a few distinct functional groups that are characterized by behavior: traplining hummingbirds repeatedly and circuitously visit flowers, often traveling long distances, while territorial hummingbirds are aggressively possessive of flowers in a home range. It turns out that Heliconia tortuosa is picky about which of these groups contributes to its pollination, and preferentially accepts pollen from traplining hummingbirds, specifically those featuring a long, curved bill. Presumably, their bill shape facilitates maximal nectar extraction which is used as a cue by the plant to become receptive to pollen.  Many hummingbirds visit the Heliconia tortuosa flower, but few induce pollination because of the straight shape of their bill. The shape and size of the Heliconia tortuosa flower in relation to the shape and size of the beak of the pollinator hummingbird constitutes the emergence of a complex plant behavior.

Heliconia wagneriana

Heliconia wagneriana

 

 

 

 

 

 

 

 

 

Dusty’s research is focused on trying to understand how Heliconia tortuosa evolved the capacity to recognize and preferentially invest in pollination by certain pollinator hummingbirds. His work consists of testing for ‘pollinator recognition’ of pollinators across a select subset of species across the Heliconia genus, comprised of 200-250 species, and subsequently using molecular techniques to infer the presence or absence of pollinator recognition across
 the family. Among these several hundred different species of Heliconia, the flowers are morphologically distinct and vary in size from short to long,  straight to curved (even up to a 90-degree angle!). Dusty’s objective is to determine if pollinator recognition is a common trait among morphologically distinct Heliconia species, and uncover the evolutionary significance of this cryptic specialization. While conducting fieldwork at Las Cruces Biological Station in Costa Rica, which featured a garden full of Heliconia, Dusty collected over 1,000 styles (the female reproductive organ in flowering plants) to assay pollen-tube growth rates across various treatments by epi-fluorescence microscopy back at OSU.

Tropical montane forest

Unraveling the tangled evolutionary biology of plants and pollinators is critical for understanding how the loss of certain pollinators might impact plant pollination. If a flower is visited by a variety of different pollinators, the loss of one pollinator might not seem like a big deal. However, if only a small number of the total number of pollinators visiting the flower are capable of inducing pollination, the loss of a true pollinator might be devastating for a plant’s ability to reproduce.

A sample of the morphological diversity in Heliconia flowers

As an undergrad at Colorado State University, Dusty studied Ecosystem Science, which consisted of learning about how nutrients and energy flow through an ecosystem. Dusty cites his high school AP Biology teacher as having a major influence on his desire to study science in college. During the first week of his freshman year, Dusty applied to work in a lab doing DNA barcoding; over the span of 4 years, he conducted over 10,000 PCR reactions! Following completion of his undergrad, Dusty planned to climb mountains in South America for a year, but unexpected circumstances expedited his enrollment in graduate school at OSU to pursue research related to pollinator recognition. Following completion of graduate school, Dusty would like to continue in academia as a professor, and possibly open a bread shop featuring a wood-fired oven, equipped with statistical models to ensure a perfect loaf of bread.

Join us on Sunday May 21st at 7PM on KBVR Corvallis 88.7FM or stream live to hear more about Dusty’s pollinator recognition research and journey through graduate school.

Motor proteins—and people—can change directionality

It took three years of adventures after college—including stints as a ski instructor, barista and a commercial chemist—before Andrew Popchock knew that he wanted to return to the lab to pursue a PhD at OSU’s Department of Biochemistry and Biophysics.

Two microtubules slide across each other by the walking of motor proteins sandwiched between them

Andrew’s research takes place at Dr. Weihong Qiu’s Single-Molecule Biophysics Laboratory and focuses on kinesin-14s—motor proteins found in eukaryotic cells. These motor proteins in cells travel along microtubules to create and maintain the mitotic spindle, which are macromolecular structures that are responsible for chromosome segregation during cell division.

By using an imaging technique called TIRF microscopy, a team of researchers from Dr. Qiu’s lab discovered that a kinesin-14 found in fungus cells called KlpA can change direction along its cytoskeleton tracks. KlpA is the first motor protein of its kind that researchers have discovered that demonstrates this type of bidirectional movement. The results of their study were recently published in Nature Communications.

Total Internal Reflection Fluorscence (TIRF) microscopy image of two microtubules sliding across each other

The motor protein that Andrew studies could be important in helping researchers understand cancer growth. This could have implications for drug treatment therapy, potentially guiding the creation of motor protein-based molecular devices for more controlled drug delivery in cancer treatments.

 

Andrew on the Oregon Coast

Growing up, Andrew was interested in physics and biology, but it wasn’t until he worked in a lab under the direction of a graduate student at Washington State University that he began to consider graduate studies. While working as a chemist in Idaho, he realized that he quickly reached the limit of his creative capacity and that returning to a laboratory as a graduate student at OSU would help him continue to develop his skills as a researcher.

To learn more about Andrew’s research and his path to graduate school, tune in to hear our conversation on Sunday, May 14th at 7:00 pm on 88.7 FM KBVR Corvallis or listen live online.

Bone marrow transplants save lives, but can it keep our bones strong?

What doesn’t kill you makes you stronger. This phrase is often helpful when fighting adversity, but it does not hold true for patients suffering from diseases such as leukemia, tuberculosis, and certain forms of anemia. Current medical science allows us to save lives, but their quality of life is curtailed because bones are typically weaker and prone to breaking as a result of cancer treatments. Patients may have endured countless surgeries, drug rehabilitation, and physical therapy only to have their level of physical activity severely limited because of the complications posed from fragile bones.

Goldner’s trichrome staining, in which mineralized bone matrix, erythrocytes, and cytoplasm were stained green, orange, and red, respectively. Credit: Burr, David B., and Matthew R. Allen, eds. Basic and applied bone biology. Academic Press, 2013.

At the center of this problem is bone marrow, and working to find a solution is Richard Deyhle, a Masters student studying Radiation Health Physics, believes we may have found a way to treat these cancers while also increasing our bone strength to previous levels of functionality. This work is in the proof-of-concept phase so it’s still early in the framework of medical application to the public but there is little doubt this can provide miraculous benefits to cancer patients providing them a higher quality of life.

Richard working on generating a 3D visualization of Micro-Computed Tomography data.

 

First it’s important to understand that even though bone marrow only accounts for ~4% of our body mass, it’s also the production source of red blood cells (carrying oxygen throughout our body), blood platelets (helping to clot blood to prevent blood loss), and white blood cells (major players in our immune system keeping us healthy). Cancer treatments focus on treating and restoring the healthy function of bone marrow so we can live. Kind of important stuff! But the health of the bone marrow does not always correspond to strong bones. This is where Richard, working under Urszula Iwaniec & Russell Turner in the Skeletal Biology Lab at OSU, brings their expertise to find new ways to treat malfunctioning bone marrow.

Micro-Computed Tomography image of the radius bone from a rat from Space Shuttle Mission, STS-41.

Bone marrow is made of many subcomponents, and standard medical practice is to replace a patient’s bone marrow (containing all subcomponents) with bone marrow from a compatible donor. Depending on the extent of transplant, there are somewhere in the neighborhood of 5,000,000 cells that are replaced representing the mosaic of cells that make up bone marrow. Richard is using a more targeted approach of purifying bone marrow and isolating a subcomponent, called Hematopoietic stem cells, so a transplant will only need a few thousand of these special cells to perform the same function as the much larger transplant. Using mice models his lab has found similar results as other researchers showing the use of pure Hematopoietic stem cells, instead of bulk bone marrow material, has similar effects on bone marrow functionality. Through the use of Green Fluorescent Protein (as a bookmark in the newly injected cells allowing researchers to trace where cells move through the body), the Skeletal Biology Lab hopes to better understand the mechanism of bone strength resilience to a healthy functioning bone marrow. Like any good scientific study, much more work needs to be done to examine these results and verify effect sizes, but the road ahead looks promising.

Richard’s childhood home was nestled away from large cities that allowed him to stare at the sky and see the Milky Way in all its beauty. Even at a young age he wondered about space, wondered how far humans can go, and wondered how he can help keep future explorers safe as we explore distant worlds. These youthful curiosities of space eventually lead to his research passion of understanding how radiation affects the human body. If all his plans work out he hopes to transition into a PhD program where he can focus more closely on making sure our fragile human bodies can explore worlds beyond ours.

If you’re interested in new medical advancements that can be used to treat cancer or astronauts, you cannot miss this episode! Be sure to tune in Sunday May 7th at 7PM on KBVR Corvallis 88.7FM or by listening live.